Figure 5.

Spatial memory assessment after GAL and the Y1R agonist alone and combined in the object-in-place memory task. (a) Schematic representation of the trials completed in the object-in-place task. The animals performed the task in three phases, divided 24 h from each other, where they explored freely for ten minutes in the habituation phase without objects, three minutes in the training phase with four different objects, and finally, three minutes in the test phase with two of the objects with the exchanged position. To achieve memory consolidation, the pharmacological treatments were administered intracerebroventricularly (icv) to the different groups of animals 24 h before the testing phase. (b) Performance on the object-in-place task showing the ability of rats to discriminate the exchanged objects at 24 h post-training after the icv administration of GAL in combination with the Y1R agonist. An improvement in the object-in-place performance was observed after GAL and the Y1 agonist co-administration following a 24 h delay. Besides, this effect is counteracted by the GAL 2 receptor (GALR2) antagonist M871. Data are presented as the mean ± SEM of the discrimination ratio on the test phase. n = 6 animals in each group. * p < 0.05 vs. Y1R agonist and GAL + Y1R + M871; ** p < 0.01 vs. aCSF; *** p < 0.001 vs. GAL according to one-way ANOVA (F4, 25 = 3.56) followed by Newman–Keuls post-hoc test. Statistical values are presented in Supplementary Table S1. Abbreviations: aCSF = Control (artificial cerebrospinal fluid), GAL = galanin (3 nmol), Y1R agonist = Y1R receptor agonist [Leu³¹-Pro³⁴]NPY (3 nmol), GAL + Y1R = co-administration of GAL and Y1R, GAL + Y1R + M871 = co-administration of GAL, Y1R, and GALR2 antagonist M871 (3 nmol).